As a spotty youth, I would set the rear brake light to come on only after a very hard push (cable brakes of course). Allowing for speed 'modulation' without a tell-tale light on, when seeing the police. Not needed today, as I only ride up to 5% below the limit, officer.
I miss little bikes that could be thrashed.
Anyway - Hi Vince, because you changed the calipers, you have changed the brake efficacy when compared to the hydraulic pressure within the system. So, yes, you will have that offset, a more sensitive switch is needed.. The hydraulic pressure in your system is now lower than before (for a given stopping effect).